| 摘要 |
PURPOSE:To improve the circumference balance collapsion of the fusion bonded zone and eliminate gas deviation flow by grasping the timings at which the differences in the furnace top gas density of the same radius level by each direction and shaft pressure values occur at the blast furnace operation and performing reducing blowing down operation to lower the raw descending material level then doing such things as operation controlling. CONSTITUTION:At the blast furnace operation, the timings at which the differences in the furnace top gas density of the same radius level by each direction and shaft pressure values occur are grasped. Thence, the reducing blowing down operation is done to lower the raw descending material level down to the shaft lower part, barrel or bosh part below the existing fusion-bonded zone level, so that the fusion-bonded zone is rebuilt. Namely, by lowering the descending raw materials down to the shaft lower part or bosh below the existing fusion-bonded zone level, the fusion-bonded zone volume after the reduction becomes 50% or less of the existing fusion-bonded zone volume. According to this method, the in-furnace gas reduction efficiency improves and the Si variations in iron and fuel ratio may be lowered. |
